Such tire-pressure monitoring units for monitoring the tire filling pressure of a motor vehicle are known. During operation, these tire-pressure monitoring units transmit information about the tire filling pressure to a central unit of the motor vehicle in a wireless manner. The tire-pressure monitoring units of all tires of a motor vehicle form a tire-pressure monitoring system together with the central unit. Within the tire, said tire-pressure monitoring units for monitoring the tire filling pressure are leaned or pressed against the rim.
In order to protect the electronic components arranged within the housing of the tire-pressure monitoring unit against moisture, it is known to insert the electronic components in a lower housing shell of the tire-pressure monitoring unit and, afterwards, cast the lower housing shell with a curing casting material in such a way that the electronic components are completely enclosed and protected by the casting material.
However, the disadvantage of said approach lies with the fact that the tire-pressure monitoring unit has a great mass because the housing of a such tire-pressure monitoring unit is completely cast with a curing casting material, leading to high and rapidly increasing centrifugal forces at high driving speed, since such tire-pressure monitoring units are arranged on the rim within the tire of the motor vehicle. In the worst case, the resulting centrifugal forces may cause the tire-pressure monitoring unit to detach from the rim and be damaged, and a valve mounted on the tire-pressure monitoring unit detaches and breaks.